Saltwater aquarium setup?

i have a 56 gallon aquarium and i want to make it a saltwater tank, could someone with saltwater experience please help me to try to get started on the right foot. i have the tank a stand a canister and a HOB filter that together are can filter 120 gallon capacity i also have flora max as the substrate and i read that this can be used in saltwater as well but i kinda want a white substrate (what is a good substrate?) i have a 900 maxi jet power-head to circulate the water well. i know i have to add the proper amount of sea salt but is there anything else i am missing? if you could just provide a step by step setup method or a website that could help me along that would be great. (not looking for criticism on tank size here) tank will mostly house 2-4 clown fish, 1-2 yellow tangs, 1-2 blue tangs for starters (may add green gobys a chocolate chip starfish and maybe a sea horse) is this good or bad?